R: Class for the Results of 2-Stage Maximum Likelihood (TSML)...

twostage-class {semTools} | R Documentation

## Class for the Results of 2-Stage Maximum Likelihood (TSML) Estimation for Missing Data

### Description

This class contains the results of 2-Stage Maximum Likelihood (TSML) estimation for missing data. The `summary`, `anova`, `vcov` methods return corrected SEs and test statistics. Other methods are simply wrappers around the corresponding `lavaan` methods.

### Usage

    ## S4 method for signature 'twostage'
    show(object)

    ## S4 method for signature 'twostage'
    summary(object, ...)

    ## S4 method for signature 'twostage'
    anova(object, h1 = NULL, baseline = FALSE)

    ## S4 method for signature 'twostage'
    nobs(object, type = c("ntotal", "ngroups", "n.per.group",
      "norig", "patterns", "coverage"))

    ## S4 method for signature 'twostage'
    coef(object, type = c("free", "user"))

    ## S4 method for signature 'twostage'
    vcov(object, baseline = FALSE)

    ## S4 method for signature 'twostage'
    fitted.values(object, model = c("target", "saturated",
      "baseline"), type = "moments", labels = TRUE)

    ## S4 method for signature 'twostage'
    fitted(object, model = c("target", "saturated",
      "baseline"), type = "moments", labels = TRUE)

    ## S4 method for signature 'twostage'
    residuals(object, type = c("raw", "cor", "normalized",
      "standardized"))

    ## S4 method for signature 'twostage'
    resid(object, type = c("raw", "cor", "normalized",
      "standardized"))

### Arguments

`object` | An object of class `twostage`.
`...` | arguments passed to `parameterEstimates`.
`h1` | An object of class `twostage` in which `object` is nested, so that their difference in fit can be tested using `anova` (see Value section for details).
`baseline` | `logical` indicating whether to return results for the baseline model, rather than the default target (hypothesized) model.
`type` | The meaning of this argument varies depending on which method it it used for. Find detailed descriptions in the Value section under `coef`, `nobs`, and `residuals`.
`model` | `character` naming the slot for which to return the model-implied sample moments (see `fitted.values` description.)
`labels` | `logical` indicating whether the model-implied sample moments should have (row/column) labels.

### Value

`show` | `signature(object = "twostage"):` The `show` function is used to display the results of the `anova` method, as well as the header of the (uncorrected) target model results.
`summary` | `signature(object = "twostage", ...):` The summary function prints the same information from the `show` method, but also provides (and returns) the output of `parameterEstimates(object@target, ...)` with corrected SEs, test statistics, and confidence intervals. Additional arguments can be passed to `parameterEstimates`, including `fmi = TRUE` to provide an estimate of the fraction of missing information.
`anova` | `signature(object = "twostage", h1 = NULL, baseline = FALSE):` The `anova` function returns the residual-based χ^2 test statistic result, as well as the scaled χ^2 test statistic result, for the model in the `target` slot, or for the model in the `baseline` slot if `baseline = TRUE`. The user can also provide a single additional `twostage` object to the `h1` argument, in which case `anova` returns residual-based and scaled (Δ)χ^2 test results, under the assumption that the models are nested. The models will be automatically sorted according their degrees of freedom.
`nobs` | `signature(object = "twostage", type = c("ntotal", "ngroups", "n.per.group", "norig", "patterns", "coverage")):` The `nobs` function will return the total sample sized used in the analysis by default. Also available are the number of groups or the sample size per group, the original sample size (if any rows were deleted because all variables were missing), the missing data patterns, and the matrix of coverage (diagonal is the proportion of sample observed on each variable, and off-diagonal is the proportion observed for both of each pair of variables).
`coef` | `signature(object = "twostage", type = c("free", "user")):` This is simply a wrapper around the corresponding `lavaan` method, providing point estimates from the `target` slot.
`vcov` | `signature(object = "twostage", baseline = FALSE):` Returns the asymptotic covariance matrix of the estimated parameters (corrected for additional uncertainty due to missing data) for the model in the `target` slot, or for the model in the `baseline` slot if `baseline = TRUE`.
`fitted.values, fitted` | `signature(object = "twostage", model = c("target", "saturated", "baseline")):` This is simply a wrapper around the corresponding `lavaan` method, providing model-implied sample moments from the slot specified in the `model` argument.
`residuals, resid` | `signature(object = "twostage", type = c("raw", "cor", "normalized", "standardized")):` This is simply a wrapper around the corresponding `lavaan` method, providing residuals of the specified `type` from the `target` slot.

### Slots

`saturated`

  A fitted `lavaan` object containing the saturated model results

`target`

  A fitted `lavaan` object containing the target/hypothesized model results

`baseline`

  A fitted `lavaan` object containing the baseline/null model results

`auxNames`

  A character string (potentially of `length == 0`) of any auxiliary variable names, if used

### Objects from the Class

Objects can be created via the `twostage` function.

### Author(s)

Terrence D. Jorgensen (University of Amsterdam; TJorgensen314@gmail.com)

### See Also

`twostage`

### Examples

    # See the example from the twostage function

[Package semTools version 0.5-0 Index]